Scotch malt whisky production involves several stages, the most important of which is arguably the maturation process by which new-make whisky is matured for several years in wooden casks.
Whisky is typically ˜60% water, ˜40% ethanol (and ˜0.1% other constituents), when it is casked, but during the maturation process (which typically takes ten to twenty years) a proportion of the fluid volume in the cask is lost to the atmosphere. This is affectionately referred to in the trade as the “angels' share”.
The angels' share is, in Scotland, typically around 2% volume per annum. Elsewhere in the world the loss can be as high as 5% per annum. Some whisky producers may have tens of millions of whisky casks undergoing maturation at any one time so these losses are clearly significant.
In fact, the angels' share is reported to cost on the order of 10-15% of the production cost. It is therefore desirable to reduce or prevent this lost volume of product. Experiments have been conducted in which casks have been shrink-wrapped; however while fluid loss is eliminated (or significantly reduced) there is a corresponding elimination (or significant reduction) in air ingress which is believed to negatively affect the maturation process and hence the taste of the final product.
Wines, cognacs, armagnacs, sherries, ports, whiskeys (e.g. Bourbon) and beers may also be matured in barrels (as may balsamic vinegar), and the angels' share loss problem is also known to affect these maturation processes (to lesser or greater extents). This is therefore a wide reaching problem, and a solution that at least partially solves the problem will provide major economic benefits.
In view of the foregoing, it is an object of at least one embodiment of an aspect of the present invention to provide an apparatus that can reduce or prevent fluid loss during a maturation process, and a corresponding method.
It is also an object of at least one embodiment of an aspect of the present invention to provide a system for monitoring and/or controlling a maturation process, and a corresponding method.